package day07;

import java.util.Random;

public class VerificationCode {
    public static void main(String[] args) {
        String code =generateVeriCode(100);
        System.out.println("验证码为："+code+"有效时间10秒");
    }
    public static String generateVeriCode(int len){
        String code="";
        char[] chs={'a','b','c','d','e','f','g','h','i','j','k',
                'l','m','n','o','p','q','r','s','t','u','v',
                'w','x','y','z','A','B','C','D','E','F','G','H'
                ,'I','J','K','L','M','N','O','P','Q','R','S','T',
                'U','V','W','X','Y','Z','1','2','3','4','5','6',
                '7','8','9','0'};
        for(int i=1;i<=len;i++){
            int index=(int)(Math.random()*chs.length);
            code+=chs[index];//回获取随机字符并拼到code中}
        }

        return  code;
    }
    public static String generateVeriCode01(int len){
        String code="";
        char[] chs={'a','b','c','d','e','f','g','h','i','j','k',
                'l','m','n','o','p','q','r','s','t','u','v',
                'w','x','y','z','A','B','C','D','E','F','G','H'
                ,'I','J','K','L','M','N','O','P','Q','R','S','T',
                'U','V','W','X','Y','Z','1','2','3','4','5','6',
                '7','8','9','0'};
        Random rand=new Random();
        for(int i=1;i<=len;i++){
            int index=rand.nextInt(chs.length);//随机生成下标（0到61）
            code+=chs[index];//回获取随机字符并拼到code中}
        }

        return  code;
    }

}
